Service-meter circuits.



H. D. GURRIBR & G. WOLF.

SERVICE METER CIRCUITS.

APPLICATION FILED NOV. 7, 1007.

1,026,151. Patented May 14,1912.

UNITED STATES PATENT OFFICE.

HIRAM D. CURRIER, OF CHICAGO, ILLINOIS,

AND GEORGE WOLF, OF NEW YORK, N. Y.,

ASSIGNORS TO WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORA- TION OF ILLINOIS.

SERVICE-METER CIRCUITS.

To all whom it may concern Be it known that we, IIIRAM D. Gunmen, of Chicago, Cook county, Illinois, and GEORGE Tour. of New York, New York county, New York, citizens of the United States, have invented a certain new and useful Improvement in Service-Meter Circuits, of which the following is a full, clear, concise, and exact description.

Our invention relates to a telephone service meter, and its object is to provide an improved organization of circuits and apparatus whereby a given connection cannot be registered more ,than once.

A further object is to provide means whereby, after a connection has once been registered, a subsequent attempt to register the same connection will cause the operation of a signal and indicate such fact to the operator.

One feature of our invention consists in an arrangement of circuits and apparatus whereby more than a single registering of a given connection on either the line or position meter is rendered impossible.

A further feature of our invention is the arrangement whereby a guard signal is caused to operate if an attempt is made to register a given connection more than once.

More specifically, our invention consists in an arrangement of circuits adapted to be associated with the cord circuit by the depression of the registering key, whereby, if the service meter is in its unoperated position, a call will be registered on the line service meter, and also on the position meter; but, after such registering has once been effected, a subsequent depression of the registering key will cut the position meter out of circuit and preferably will also close a circuit through a guard lamp or other warning signal.

WVe will describe our invention more particularly by reference to the accompanying drawing, which is a diagram illustrating the preferred embodiment thereof.

The telephone exchange system illustrated is in general of a well-known type, and hence we shall give a detailed description of only such parts as embody our invention, or are more directly related thereto. Each line has at its substation A the usual telephone apparatus. The telephone line includes at the central office the usual line relay C, controlling the line signal Z, and is Specification of Letters Patent.

Patented May 14, 1912.

, 1907. Serial No. 401,068.

connected by way of the contacts of the usual cut-off relay D to a common battery B. The winding of relay D has a resistance of, say, thirty ohms, and is included, as usual, in a conductor 3, which connects with the test ring a to ground. The electromagnet E of the line meter M is placed in multiple with the cut-off relay D. Said magnet E has a high-resistance winding 6, as, for example, of five hundred ohms, and also a normally-open low resistance locking winding 0 of, for example, forty ohms, adapted to be closed in the attracted position of the armature c in the operation of the line meter M.

The cord conduit is of a well-known type, with the exception that a resistance R of, for example, one hundred ohms, is included in the third strand 4, said resistance being normally short-circuited through the switch K. The improvement in which our invention more particularly consists lies in the circuit adapted to be connected with the third strand by the key or switch K for controlling the operation of the service meter M. The connection register switch K when closed is adapted to bridge a local circuit to ground from the point 8 in the third strand of the cord circuit. Said local circuit includes a grounded battery B of higher voltage than the common battery B. To have found, with the values assigned to the various resistances as indicated, and with the usual twenty-four-volt common battery B, that the battery B of from thirty-four to thirty-eight volts gives satisfactory results. In the lead from the battery B to the contact 5 of the service meter key K, there are two relays, F and G of, for example, half an ohm and ten ohms resistance, respectively. The relay G is preferably a double-spool telegraph relay, such as shown. The electromagnet H, which controls theposition meter M, is in a shunt of the relay G, said shunt circuit being normally open at contact f, controlled by relay F. The armature g of relay G is included in said shunt circuit, and when attracted is adapted to open said shunt circuit at back contact 6, and to close a front contact 7. A current sufiicient to operate the relay G to close contact 7 will thus close a circuit from the grounded battery B through relay F, contacts f and 7, and guard lamp 8', for the purposes hereinafter set forth. The magnet H in the attraction of its armature it operates the registering mechanism of the position meter M, and also closes a local circuit including the common battery 13 and a lamp or other signal .9, thus indicating the operation of said meter. The resistance R is sufliciently high as, for example, a resistance of one hundred ohms, to lessen the current from the high voltage battery B" dividing at the point 8 and seeking a path to ground through the battery B. The resistance R is not so high, however, but that it permits a sufficient flow of current from the battery B, during the movement of the switch K from its back to its front contact, to hold the armature of the cut-off relay D in its attracted position and to maintain the locking circuit 6 in its closed condition after the meter M has operated.

The operation of the system is as follows: The operator having noticed, through the operation of the line lamp Z, that a subscriber is making a call for a connection, in'answering, inserts the plug 79 in the answering ack j of the line. A circuit is thus completed from battery B through the third strand 4, ring a, conductor 3, relay D to ground, resulting in the operation, in the usual manner, of the cut-off relay D. The magnet E, in multiple with relay D, is not operated, owing to the high resistance of its windingc. The operator proceeds in the usual way to obtain the called subscriber, and if successful depresses the key K to operate the service meter M of the calling line. When said key is depressed the relay F operates immediately, thereby preventing the operation of the relay G by closing the shunt circuit about the same. Said shunt circuit includes the electromagnet H, but said magnet does not as yet operate, owing to the highresistance in the circuit thus closed. In response to the initial flow of current from battery B, the magnet E operates, thereby closing Y its low resistance locking winding 6. As a result of this reduction of resistance in its circuit, the mag net H operates and lights the lamp 8, thereby indicating that both the line and position meters have operated. The armature e of the magnet '13 will be held by the locking winding 6 in its actuated position even when the key IQ is released, as long as the plug 79 remains inserted in the jack j. If now the operator should again depress the key K, the meter M being already in operated position,there would be no second operation thereof. The low resistance winding 6, in this case, moreover, would allow a considerable flow of current, permitting the operation of relay G, as well as relay F, and thus open contact 6 and close contact 7. As a result, the magnet H is cut out of circuit and its operation prevented, and the circuit of the guard lamp 8 is closed at contaots 7 and f. The lighting of the guard lamp would indicate to the operator that the connection had already been registered. It is obvious that upon the withdrawal of the plug at the termination of the call, the parts will be restored to their normal positions.

It will be seen that our invention provides means whereby after the position and line meters have operated to register a given connection, all subsequent attempts to operate said meters for the same connection will be non-effective, and will result merely in the operation of a guard lamp to indicate the fact that the connection had been previously registered.

We claim r 1. In a telephone system the combination with a telephone line, of a central oflice con nection switch, an electromagnetically operated line meter having acircuit controlled at one point by said connection switch, a

local circuit including an independent source of high potential current and an electromagnetically operatedposition meter, a connec tion register switch for completing said local circuit through said line meter and thereby operating said meters, a magnet energized upon the operation of said connection register switch while said line meter is in its operated position, and a device operated by said magnet when excited directly controlling said position meter to prevent the operation thereof.

2. In a telephone system, the combination with a telephone line, of a central oifice connection switch, an electromagnetically operated line meter having a circuit controlled at one point by said connection switch, a local circuit including an electromagnetically operated position meter, a guard lamp associated. with said local circuit, a connec tion register switch for completing said local circuit through said line meter and thereby operating said meters, a magnet energized upon the operation of said connection register switch while said line meter is in its operated position, and a device operated by said magnet when excited directly controL ling said position meter to prevent the operation thereof and to operate said guard signal.

3. In a telephone system, the combination with a telephone line, of a central ofiice connection switch, an electromagnetically-operated line meter having a circuit controlled at one point by said connection switch, a local circuit including an electromagneticallyoperated posit-ion meter, a connection register switch for completing said localcircuit through said line meter and thereby oper ating both of said meters, means in the circuit of said meters for increasing the flow of current in said circuit upon the operation of said meters, and a relay responsive only to said increased flow of current and by its operation preventing more than a single operation of said position meter for a given connection.

4. In a telephone system, the combination with a telephone line, of a central oflice connection switch, an electromagnetically-operated line meter havingacircuit controlled at one point by said connection switch, a local circuit including an electromagneticallyoperated position meter, a connection register switch for completing said local circuit through said line meter and thereby operating both of said meters, a guard signal, means in the circuit of said meters for increasing the flow of current in said circuit upon the operation of said meters, and a relay responsive only to said increased flow of current and by its operation preventing more than a single operation of said position meter for a given connection, and for operating said guard signal in response to a further closure of said connection register switch.

5. In a telephone system, the combination with a telephone line, of a central otlice connection switch, a line meter having a circuit adapted to be completed by said connection switch, a local circuit including a high resistance relay, a low resistance relay and an independent battery in series with one another, a shunt of said high-resistance relay controlled by said low resistance relay, a position meter included in said shunt circuit, and a connection register switch for completing said local circuit through said line meter.

6. In a telephone system, the combination with a telephone line, of a central office connection switch, a line meter having a circuit adapted to be completed by said connection switch, a local circuit including a high resistance relay, a low resistance relay and an independent battery in series with one another, a shunt of said high resistance relay controlled by said low resistance relay, a position meter included in said shunt circuit, a switch in said shunt circuit controlled by said high resistance relay, for cutting said position meter out of circuit, and a connection register switch for completing said local circuit through said line meter.

7. In a telephone system, the combination with a telephone line, of a central otlice connection switch, a line meter having a circuit adapted to be completed by said connection switch, a local circuit including a high rc sistance relay, a low resistance relay and an independent battery in series with one another, a shunt of said high resistance relay controlled by said low resistance relay, a position meter included in said shunt circuit, a switch in said shunt circuit, controlled by said high resistance relay for cutting said position meter out of circuit, a guard lamp arranged to be included in the circuit upon the operation of said last-named switch, and a connection register switch for completing said local circuit through said line meter.

8. In a telephone system, the combination with a telephone line, of a central ollice connection switch, an electromagnetically-actuated line motor having a circuit adapted to be completed by said connection switch, the actuating magnet of said meter being provided with a high resistance operating winding and a low resistance locking winding, a local circuit including a high resistance relay, a low resistance relay and a high potential battery in series with one another, a shunt of said high resistance relay controlled by said low resistance relay, a posi tion meter included in said shunt circuit, a switch in said shunt circuit controlled by said high resistance relay, for cutting said 7 position meter out of circuit, a guard lamp arranged to be included in the circuit upon the operation of said last-named switch, and a connection register switch for com pleting said local circuit through said line meter.

9. In a telephone system, the combination with a telephone line, of a central oflice plug and cord circuit, a line meter having a circuit adapted to be completed by said plug and cord circuit, a normally short-circuited resistance in the third strand of said cord circuit, a local circuit including a high resistance relay, a low resistance relay and a high potential battery in series with one another, a shunt of said high-resistance relay controlled by said low resistance relay, a position meter included in the shunt circuit, and a connection register switch arranged for bridging said local circuit to ground from a point in the third strand of said cord circuit between said resistance included therein, and the plug.

10. In a telephone system, the combination with a telephone line, of a central offiee plug and cord circuit, an electromagnetically-actuated line meter having a circuit adapted to be completed by said plug and cord circuit, the actuating magnet of said meter being provided with a high resistance operating winding and a low resistance locking winding, a normally short-circuited resistance in the third strand of said cord circuit, a local circuit including a high resistance relay, a low resistance relay and a high potential battery in series with one another, a shunt of said high resistance re lay controlled by said low resistance relay, a position meter included in the shunt cir' cuit, a switch in said shunt circuit controlled by said high resistance relay, for cutting said position meter out of circuit, a guard lamp arranged to be included in the circuit upon the operation of said 1astnamed switch, and a connection register switch arranged for bridging said local circuit to ground from a point in the third strand of said cord circuit between said resistance included therein, and the plug.

11. In a telephone system, the combination with a telephone line, of a central office connection switch, an electroinagnetically operated line meter having a circuit controlled at one point by said connection switch, a local circuit including an independent source of high potential current and an electromagnetically operated position meter, a connection register switch for completing'said local circuit through said line meter and thereby operating said meters, a relay energized upon the operation of said connection register switch while said Wolf:

line meter is in its operated position, and

contacts controlled by said relay included in said local circuit.

In witness whereof, we hereunto subscribe our names this 17th day of October A. D., 1907, and 21st day of October A. D., 1907,

respectively.

HIRAM D. CURRIER. GEO. WOLF. Witnesses to the signature of Hiram D. Currier:

RALPH Gr. JOHANSEN, Roy T. ALLowAY. Witnesses to the signature of George HARVEY L. BURNS, H. L. DANAH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

